package com.dexstudio.threads;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;

public class AsyncTaskManager implements IProgressTracker, OnCancelListener {

	private final OnTaskCompleteListener mTaskCompleteListener;
    private final ProgressDialog mProgressDialog;
    private Task mAsyncTask;
    
    public AsyncTaskManager(Context context, 
    		OnTaskCompleteListener taskCompleteListener) {
    	// Save reference to complete listener (activity)
    	mTaskCompleteListener = taskCompleteListener;
    	// Setup progress dialog
    	mProgressDialog = new ProgressDialog(context);
    	mProgressDialog.setIndeterminate(true);
    	mProgressDialog.setCancelable(true);
    	mProgressDialog.setOnCancelListener(this);
    }
    
    public void setupTask(Task asyncTask) {
    	// Keep task
    	mAsyncTask = asyncTask;
    	// Wire task to tracker (this)
    	mAsyncTask.setProgressTracker(this);
    	// Start task
    	mAsyncTask.execute();
    }
	
	public void onCancel(DialogInterface dialog) {
		// Cancel task
		mAsyncTask.cancel(true);
		// Notify activity about completion
		mTaskCompleteListener.onTaskComplete(mAsyncTask);
		// Reset task
		mAsyncTask = null;
	}

	public void onProgress(String message) {
		// Show dialog if it wasn't shown yet or was removed on configuration (rotation) change
		if (!mProgressDialog.isShowing()) {
		    mProgressDialog.show();
		}
		// Show current message in progress dialog
		mProgressDialog.setMessage(message);
	}

	public void onComplete() {
		// Close progress dialog
		mProgressDialog.dismiss();
		// Notify activity about completion
		mTaskCompleteListener.onTaskComplete(mAsyncTask);
		// Reset task
		mAsyncTask = null;
	}
	
    public Object retainTask() {
    	// Detach task from tracker (this) before retain
    	if (mAsyncTask != null) {
    	    mAsyncTask.setProgressTracker(null);
    	}
    	// Retain task
    	return mAsyncTask;
    }

    public void handleRetainedTask(Object instance) {
    	// Restore retained task and attach it to tracker (this)
    	if (instance instanceof Task) {
    	    mAsyncTask = (Task) instance;
    	    mAsyncTask.setProgressTracker(this);
    	}
    }

    public boolean isWorking() {
    	// Track current status
    	return mAsyncTask != null;
    }
}
